RAV 4 O/S/F squealing

[Dan Wigglesworth]

Hi all,

I have just purchased a 2006 (55 plate) 3 door Rav 4 as a run around, I have noticed that when turning right there's a high pitched squealing from what seems to be the front right of the vehicle. When the steering wheel is dead straight there's no noise, as soon as the wheel is turned the squealing appears. When the car is running and stationary and the wheel is turned the noise doesn't appear. I have had the wheel off and cant see anything rubbing/catching on the disc and the pads seem fine. The noise does seem to dampen when the brakes are pressed.

Any ideas please before I go to the garage?

 

Thanks. 

[Mike169]

Hi Dan.

If you jack the car up do both of the front wheels spin as freely as each other.

The fact you have commented on the noise changes when the brake pedal is depressed a bit suggests either the brake piston is a bit seized ir the sliding mechanism is a bit seized.

If the o/s/f wheel is harder to spin then a strip down of the brake calliper, very carefully clean up all the parts, scrape off any rust, emery cloth is a good idea, get say WD40 on the piston under the seal, use say copper slip on the sliding metal parts when reassembling.

If you end up doing this I suggest you do it to the other side too.

Regards, Mike.

[Avalon]

Over enthusiastic application of silicon grease to the front lower guide pin can cause the rubber seal to form a vacuum which prevents the normal free movement of the calliper and pads, which is capable of producing what you describe. Strip/clean the calliper and pins.

23 hours ago, Mike169 said:

Hi Dan.

If you jack the car up do both of the front wheels spin as freely as each other.

The fact you have commented on the noise changes when the brake pedal is depressed a bit suggests either the brake piston is a bit seized ir the sliding mechanism is a bit seized.

If the o/s/f wheel is harder to spin then a strip down of the brake calliper, very carefully clean up all the parts, scrape off any rust, emery cloth is a good idea, get say WD40 on the piston under the seal, use say copper slip on the sliding metal parts when reassembling.

If you end up doing this I suggest you do it to the other side too.

Regards, Mike.

Copper slip has its place, but it’s petroleum based and technically could cause galvanic corrosion, but more importantly will dry out, silicon has replaced it for brake work and is supplied as part of the guide pin kits for a reason. WD40 is a dispersant, not a lubricant, it also has no place anywhere near the piston - it’s only £40 for a fully refurbished OE calliper inc bleed nipple or £8ish for the piston kit - I know which approach I would take...

[Notoyboy]

i can't recall whether it was a high pitch squeal, but on a previous car, I had a noise which turned out to be the dust shield coming into contact with the brake disc on turning one way whilst driving.  Judicious application of a lever eased the dust shield away from the disc.  I guess the problem happened as the wheel bearings devoped more play (nothing obvious) than when they were new.

It was a cheap & simple remedy.  Wish all car isssues were like that!

[Mike169]

Each to their own. WD40 is a fish oil based product and the fish seem to do well in the water and perhaps you could say why it should not be used as it has been used by many mechanics for many years on brake caliper piston's and which product would be used instead incase the person with the problems does not wish to replace the calipers as of course what you so to one side should be done to the other. Copper slip has been used for many years and even quoted in manuals I have read in the past so again perhaps you could comment in detail why it should not be used and which named product you feel is superior for the purpose of lubricating the sliding parts. Silicone is a sealant and sold as such. On the fitting of brake shoes it is regularly used by garages to lubricate the touching parts.so like I said each to their own. 

[Stivino]

My advice as a mechanic with over 40 years experience is not to use anything that isn't recommended for use in the area that you are working on.  That means do not use WD40 on and brake rubbers.  WD40 can be aggressive to the type of rubber used in brakes and can cause it to degrade/soften/swell etc.  It should never be used to lubricate pistons.

It's not a case of "each to their own" I'm afraid.  Go to a brake manufacturers website and follow the instructions on what to use on brakes.

[Mike169]

Hi Stivino, my use of WD40 is purely to get the pistons freed off with going into detail someone inside the car carefully pressing the brake pedal with say the caliper removed to free the piston then afterwards using brake cleaner to wash off the rust and WD40 but what I am saying is it is very good at freeing off a semi stuck piston being fish oil based and can wash rust particles. Brake cleaner in an aerosol can be used afterwards to wash off any residue off but using brake cleaner alone it will evaporate too quickly and not lubricate too well whilst the person at the caliper end watching and squeezing the piston making sure it does not pop out using a G clamp or large grips to return the piston.

[Stivino]

The formula for WD40 has never been disclosed so, what makes you think it is fish oil, which I'm quite sure it isn't?

I should also add, if you want to free off a seized piston, there is no better place for the caliper to be than bolted to the car, there is no need to remove it and it is not a two man job.  Keep it in place with a pad in, or two pads if they are well worn.  This will allow you to work the piston without fear of it coming too far out.  It will also allow you to use a lever to push the piston back in, after you have pumped it out yourself.

[Avalon]

1 hour ago, Mike169 said:

Each to their own. WD40 is a fish oil based product and the fish seem to do well in the water and perhaps you could say why it should not be used as it has been used by many mechanics for many years on brake caliper piston's and which product would be used instead incase the person with the problems does not wish to replace the calipers as of course what you so to one side should be done to the other. Copper slip has been used for many years and even quoted in manuals I have read in the past so again perhaps you could comment in detail why it should not be used and which named product you feel is superior for the purpose of lubricating the sliding parts. Silicone is a sealant and sold as such. On the fitting of brake shoes it is regularly used by garages to lubricate the touching parts.so like I said each to their own. 

 

https://www.wd40.com/myths-legends-fun-facts/

WHAT A FISH STORY!

Myth: WD-40® contains fish oil.

Fact: Consumers have told us over the years that they have caught some of the biggest fish ever after protecting their fish hooks and lures with WD-40®. We believe this legend came from folks assuming that the product must contain fish oil since it appears to attract fish.  Sorry Charlie®, it just ain’t so.

WD-40 Company has taken steps to respect and conserve the environment, and encourages its users to do the same. While WD-40® can be used to help protect fishing equipment from rust and corrosion, WD-40 Company does not recommend using WD-40® to attract fish.

 

....you were saying? Water Dispersant 40 is not something you want near brakes, silicon grease or red rubber grease are the only two products that should be used unless specifically stated otherwise by the OEM. I understand you mean well, but please consider that times have changed, we’ve taken heavy metals and asbestos out of brake parts, we’ve also stopped using copper slip.

[gjnorthall]

Copaslip / Copper slip has it’s uses but there are much better products available for brakes. Ceratec is widely used for lubrication and to minimise brake squeal. Silicon grease applied sparingly is best for slider pins. WD40 or similar is fine for freeing pistons (see TDS for compatibility with rubber etc) together with a smear of red rubber grease when the piston has been released.

Squeals on lock can often be attributed to a slipping auxiliary belt or a low level in the PAS reservoir.

[Stivino]

As has already been said, WD40 should not come into contact with brake rubbers. Brake fluid or the recommended grease are the only things that should be used to lubricate pistons and seals.

 

[Mike169]

Many people say it can't be used but many do.

I earn't my living, mending cars, HGV1 trucks, running garages, shops who had an MOT ramp that I controlled and many technicians. As long as the product is cleaned off afterwards it is fine, 45 years experience. Like I say each to their own so only one answer is not the answer. Mike.

WD40 on brakes.docx WD40 Brake Pistons.docx WD40 Pistons webpage.docx

[Stivino]

It's not each to their own, that is a very dangerous attitude to take.

I sometimes heat calipers up with oxy-acetylene until they are cherry red, to free them off.  Each to their own, eh?

[Mike169]

If that's your way of doing it then good luck to you!

[Dan Wigglesworth]

Hi all,

I went out with the car over the weekend and it seems that the noise doesn't always stop when the brakes are pressed, there also seems to be a belt noise i.e. slight slipping.

[gjnorthall]

23 hours ago, Stivino said:

As has already been said, WD40 should not come into contact with brake rubbers. Brake fluid or the recommended grease are the only things that should be used to lubricate pistons and seals.

 

The TDS on WD40 shows compatibility with various types of rubber. If you have experience of damage to brake rubber components - it would be worth detailing this to the manufacturers of WD40.

[gjnorthall]

On 7/20/2019 at 11:24 PM, gjnorthall said:

Copaslip / Copper slip has it’s uses but there are much better products available for brakes. Ceratec is widely used for lubrication and to minimise brake squeal. Silicon grease applied sparingly is best for slider pins. WD40 or similar is fine for freeing pistons (see TDS for compatibility with rubber etc) together with a smear of red rubber grease when the piston has been released.

Squeals on lock can often be attributed to a slipping auxiliary belt or a low level in the PAS reservoir.

It's worth checking belt tension and condition as well as the PAS reservoir level. Noises from these components would emanate from the right side front of the car. 

[Stivino]

6 hours ago, gjnorthall said:

The TDS on WD40 shows compatibility with various types of rubber. If you have experience of damage to brake rubber components - it would be worth detailing this to the manufacturers of WD40.

That would be a waste of time, I'm sure they already know what their product is and isn't compatible with.  However, they won't want the world to know.